The Scottish actress told The Independent that she was surprised that the Oscar-winning filmmaker was so willing to take suggestions from the HBO period drama's cast.

"You would expect that Martin Scorsese would just say, 'This is what we're doing, and this is what I want from you, now do it'. That would be totally justified," she said. "But the fact [is] that you can sort of mumble something - 'What about if...' - and he actually takes it on board and uses ideas."

Macdonald also joked that Scorsese was always able to top the Boardwalk Empire cast and crew's knowledge on virtually any subject.

"Some people would be so obnoxious and annoying about it. But he makes it interesting for you, and gets you more interested in any subject that you thought you were the king or queen of," she explained.

Boardwalk Empire has been renewed by HBO for a second season and was recently awarded the 'Best Drama Series' Golden Globe.